Quoted from Pinballs:
1) Lack of a groove in the ball launch lane. This means the ball hits the sides of the lane and loses energy, leading to many failed plunges. As a quick fix, would it be possible to produce some mylar with a vertical track on it (to keep the ball in the right direction) that could be stuck onto the PF?
I 3D printed some "ramp" like rectangles with switch grooves cut out and stuck them in the lane to try and solve this problem. It didn't fix it, in fact it made it worse by raising the ball up it caused the tip of the shooter rod to hit the ball even lower than it already does.
I removed the ramp and instead removed the two posts under the "Z" bracket on the left side, right next to the right outlane. Instead I replaced the starposts with straight metal posts and it solved the issue. It seems the ball would clip the edge of 1 of the two star posts on its way to the gate picture above. Try replacing the starposts.